Cannabidiol is the major nonpsychoactive ingredient in cannabis. Cannabidiol demonstrates a range of effects that may be therapeutically useful, including anti-seizure, antioxidant, neuroprotective, anti-inflammatory, analgesic, anti-tumor, anti-psychotic, and anti-anxiety properties. Exact mechanism of action of cannabidiol is not known, but may include effects on the orphan G-protein-coupled receptor GPR55; the transient receptor potential of vanilloid type-1 channel; the 5-HT1a receptor; and the α3 glycine receptors. GW Pharmaceuticals successfully developed the world’s first prescription medicine derived from the cannabis plant, Sativex® (buccal spray containing delta-9-tetrahydrocannabinol and cannabidiol) now approved in over 29 countries outside of the United States for the treatment of spasticity due to Multiple Sclerosis. GW Pharmaceuticals is developing Epidiolex® (a liquid formulation of pure plant-derived cannabidiol) for certain rare and severe early-onset, drug-resistant epilepsy syndromes.

Nabilone is a synthetic cannabinoid approved under the brand name cesamet for treatment of severe nausea and vomiting associated with cancer chemotherapy. Nabilone is an orally active which, like other cannabinoids, has complex effects on the central nervous system (CNS). It has been suggested that the antiemetic effect of nabilone is caused by interaction with the cannabinoid receptor system, i.e. the CB (1) receptor, which has been discovered in neural tissues.